Lifetime and Collisional Depopulation Cross Section for the 14^{2}D_{3/2} State of Rb

The lifetime τ and the cross section σ for depopulation induced by collisions with ground-state Rb atoms were measured for the 14^{2}D_{3/2} state of Rb. The experiment was performed in the gas-cell conditions in a range of Rb vapour temperatures in the vicinity of 340 K. The lifetime value τ = 1970(130) ns, agrees with the theoretical prediction with allowance for the influence of blackbody radiation as well as of the effects due to core polarizability and spin-orbit interaction. The measured cross section σ = 6.5(3.1) × 10^{-12} cm^{2} is close to the geometrical cross section. This agrees with similar observations made by other authors for the case of the lower n^{2}D states of Rb.